Contact seals, often called carbon seals, are commonly used to provide a fluid seal around a rotating shaft, particularly high speed rotating shafts used in high temperature environments such as in gas turbine engines. Such contact seals usually comprise carbon ring segments and a seal runner which abut and rotate relative to each other form a rubbing interface which creates a fluid seal around the shaft. Typically, but not necessarily, the seal runner is disposed on the rotating shaft and rotates within an outer stationary carbon ring, causing the rubbing interface between the rotating seal runner and the rotationally-stationary carbon ring. This rubbing contact however generates significant heat, given the high rotational speeds of gas turbine engine shafts, which must be dissipated. This heat dissipation is most often accomplished using fluid cooling, for example oil from the engine's recirculating oil system which is sprayed onto the external surfaces of the seal runner and/or the carbon ring. However, this spray cooling limits the size envelope and configuration possible for shaft seal installations, and further, if inadequately cooling fluid is provided or the cooling fluid cannot sufficiently reach/cover the required surfaces, sealing performance of such shaft seals can degrade.
Accordingly, an improved shaft contact seal is sought.